[Show abstract][Hide abstract] ABSTRACT: The diagnosis of thyroid dysfunction is often late in type 1 diabetic population. So, the aims of this study were 1) to evaluate the prevalences of thyroperoxydase (TPO) and thyroglobulin (Tg) autoantibodies detected by highly sensitive radioimmunological method in a cohort of 258 adult type 1 diabetic patients without evidence of clinical thyroid disease; 2) to determine whether or not measurement of TPO and/or Tg antibodies can identify subjects at risk of clinical or infraclinical thyroid dysfunction by measuring TSH in the entire group. TPO antibodies were found in 45 of the 258 diabetic patients (17%). The prevalence of TPO antibodies was not influenced by the following factors: gender, duration of disease, age at screening and at diabetes diagnosis, positivity of familial history. Tg antibodies were found in 19 patients (7%), including 13 cases with TPO antibodies. All patients without TPO antibody (n=213), including Tg-positive patients displayed TSH values in normal range. Among the 45 TPO-positive patients, 11 patients displayed infraclinical thyroid dysfunction. At the end of the 5-year follow-up, only 2/45 patients became anti-TPO negative. Thirteen of the 45 patients developed subclinical or clinical thyroid diseases (4 Graves'disease and 9 thyroiditis with hypothyroidism). By contrast, none of 45 TPO negative patients, sex and age matched with the TPO-positive patients, developed during follow-up anti-TPO positivity and/or infraclinical thyroid dysfunction. In conclusion, the determination of TPO antibodies by a highly sensitive method allows identifying diabetic patients with thyroid autoimmunity and at risk of subsequent impaired thyroid function, whatever age at diagnosis and diabetes duration. By contrast, anti-Tg determination did not give further information about subsequent thyroid dysfunction. In TPO antibody positive patients repeated thyroid clinical examination and TSH determination could be recommended to detect infraclinical thyroid dysfunction.
No preview · Article · Jan 2001 · Annales d Endocrinologie
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to determine the prevalence of thyroperoxidase (TPO) and thyroglobulin (Tg) antibodies, using a sensitive and specific radioimmunoassay method in a large cohort of 254 first-degree relatives of Type 1 diabetic patients with or without other autoimmune endocrinopathy, and to evaluate the predictive value of thyroid antibodies for impaired thyroid function in these groups. TPO and Tg antibodies were found at similar frequencies (12%) in the 254 relatives, and both antibodies were present in 23 cases (9%). Seven subjects displayed subclinical thyroid dysfunction without an abnormal free T4 level. Among first-degree relatives of probands with Type 1 diabetes alone, TPO or Tg antibodies were found in 8 subjects (6%), including 6 with both antibodies. The prevalence of TPO antibodies was significantly greater among relatives of TPO-positive than TPO-negative probands (p < 0.01). In relatives of diabetic patients with other endocrinopathy, frequencies of TPO (20%), Tg (19%) and a combination of both antibodies (15%) were significantly higher than in relatives of Type 1 diabetic patients without endocrinopathy (p < 0.001). TSH levels were abnormal in only one relative of the group without endocrinopathy but occurred in 6 relatives of the proband with overt endocrinopathy-associated diabetes (p < 0.02) in marked association with TPO antibodies (p < 10(-4). It is concluded that relatives of probands with overt endocrine autoimmune disease-associated diabetes, unlike those of probands with diabetes alone, showed increased prevalence of thyroid antibodies and thyroid dysfunction. These results argue for a different risk of thyroid autoimmunity and clinical disease in families of diabetic patients without or with overt endocrine disease. A screening of thyroid autoimmunity is highly recommended for the latter group.
No preview · Article · Oct 1997 · Diabetes & Metabolism